The Second Time Around

F rank Sinatra famously sang that “love is lovelier the second time around.”1 The same is not always true regarding research. Understanding the research on which critical care practice is based is essential to the provision of evidence-based care. Practicing clinicians and researchers need to know what has worked and what hasn’t. Knowledge about a study’s design, sample, setting, methodology, and analytical strategy can provide important information about whether the results of a study are trustworthy and whether the conclusions are likely to hold true for other groups of patients. Our knowledge about research findings may come from primary or secondary sources. Publications by the investigators who actually conducted the research are primary sources; these also may be referred to as original sources. Secondary sources report about research done by others, and often offer critique or interpretation.